These are definitely my new favorite pens! Simple, sleek and inexpensive. I
started with brown and have just gotten blue black and black. They write smooth
and even better I love drawing with them. I actually use them in combination
with copics and they don't smear. I haven't had any problems with blotches or
dryness and for the amount of use they've been getting they still haven't run
dry. The pen bodies are cute and feel comfortable to write with. Also, I
definitely feel like they're better made than the Tradio Pentel pen body, which
its plastic grip feels cheep. The only problem I've had so far is when I first
got the black refill it needed a little dab of water to start running. Other
than that an overall great pen!

These make great slim pens on their own, no CocoIro body needed. The lines are
super fine with no bleed-through on even the cheapest paper I own. I personally
have had no issues with these pens. The nibs are a bit stiff, but you can still
get some line variation, and all of the ink colors I've tried have been lovely.

This blue ink is nice and dark, though it could have been a bit darker. It has a
bit of a desaturated tone to it as well, which is very nice if you like subdued
colors, like me. :D

I found this very dry for English, but perfect for Chinese character notetaking,
it's fast enough for character writing, but not at all fast enough for English
cursive. The tip actually does good variation for character writing, too, and I
quite like that.

Still a little dry for my taste, though, and I now wonder if the other colors
would have been better.

The quality is pretty bad on these refills. The tips are very dry and the ink
does not flow worth a hoot. Even when left tip-down overnight they still do not
become saturated enough to lay down a wet line, and will instead just create a
bead of ink on the end, making a mess on the paper. Skip this one.